2176
210
NTA AbhyasNTA Abhyas 2020Excretory Products and their Elimination
Report Error
Solution:
Animals that excrete their nitrogenous waste mainly in the form of urea are known as ureotelic and the phenomenon is known as ureotelism.
Urea can be stored in the body for considerable periods of time and is least toxic. It is eliminated in the form of urine. Ureotelism is exhibited by semi-terrestrial animals, e.g. some earthworms, adult amphibians, elasmobranch (cartilaginous fishes), and mammals. The frog like other amphibians is ammonotelic in tadpole state and ureotelic in a mature state. The earthworm is similarly ammonotelic when sufficient water is available and ureotelic when water availability is reduced.